Method of manufacturing light emitting device including metal patterns and cut-out section

ABSTRACT

A light emitting device includes a support member having a mounting surface. The support member includes an insulating member having top surface and a plurality of side surfaces, a first metal pattern disposed on the top surface of the insulating member, and a second metal pattern disposed on the side surface of the insulating member such that a side surface of the second metal pattern is continuous with a top surface of the first metal pattern. The light emitting device further includes a light emitting element mounted on the mounting surface at a location of the first metal pattern, and a bonding member that bonds the light emitting element to the mounting surface. The bonding member covers at least a portion of the first metal pattern and at least a portion of the second metal pattern.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a Continuation of U.S. application Ser. No.14/243,690, filed on Apr. 2, 2014, which is a Continuation of U.S.application Ser. No. 13/229,524, filed on Sep. 9, 2011, which claimspriority from Japanese Patent Application No. 2010-203303, filed on Sep.10, 2010 and Japanese Patent Application No. 2011-180079, filed on Aug.22, 2011. The contents of these applications are incorporated herein byreference in their entireties.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates generally to the field of light emittingdevices. The present invention relates to a light emitting device thatcan be used, for example, as an indicator, a lighting apparatus, adisplay, or a backlight light source for liquid crystal display.

Description of Related Art

In recent years, various semiconductor devices have been proposed andput into practical use. Yet the demand for high performance is everincreasing. In particular, there is an increasing need for electricalcomponents that can maintain performance for long periods of time evenin severe environments. The same applies for light emitting diodes(LEDs) and other light emitting devices. Requirements for higherperformance in the area of general lighting, in-vehicle lighting, andthe like, is growing daily. Demand has increased for devices that canyield higher output (higher luminance) and higher reliability, whilehaving a low cost.

Generally, a light emitting device includes a base member on whichelectric components such as a semiconductor light emitting element(hereinafter referred to as a light emitting element) and a protectiveelement are mounted, and a conductive member for supplying electricpower to these electric components. The light emitting device mayfurther include a sealing member to protect the electric components fromthe external environment.

In such light emitting devices, various kinds of bonding members may beemployed to mount the light emitting element on the base member. Thebonding member may be made of a thermosetting resins such as an epoxyresin and a polyimide resin. The thermosetting resin may contain afiller such as Ag or silica. Furthermore, in order to meet the recentdemands of higher output of the light emitting devices, Au—Sn andSn—Ag—Cu based solder materials or materials made of a metal such assilver solder may be used to improve the heat dissipation properties andreliability of the devices, as described, for example, in JP2005-191135A. However, such bonding members described above which areemployed in the light emitting devices have lower light reflectivity andhigher optical absorptance compared to the materials which are typicallyused in a reflective member. Therefore, in the light emitting deviceshaving a conventional structure, light is absorbed by the bonding memberlocated near the light emitting element, which can causes problems dueto insufficient light being provided by the light emitting device.

For example, a bonding member containing a resin may be deterioratedand/or discolored by light and heat generated from the light emittingelement, which may result in an increase in the optical absorptance.

Even when a bonding member made of a metal which does not deteriorate isemployed, the light reflectivity of the metal materials typically usedin the bonding member is lower than that of the materials typically usedin a reflective member.

Further, when a large amount of the bonding member applied to obtainreliable bonding spreads to the surroundings of the light emittingelement, the optical loss is particularly large.

As described above, in the light emitting devices having a conventionalstructure, light may be absorbed by the bonding member located near thelight emitting element, which causes a problem in which sufficient lightcan not be extracted.

SUMMARY OF THE INVENTION

According to one embodiment, a light emitting device includes a supportmember having a mounting surface. The support member includes aninsulating member having top surface and a plurality of side surfaces, afirst metal pattern disposed on the top surface of the insulatingmember, and a second metal pattern disposed on the side surface of theinsulating member such that a side surface of the second metal patternis continuous with a top surface of the first metal pattern. The lightemitting device further includes a light emitting element mounted on themounting surface at a location of the first metal pattern, and a bondingmember that bonds the light emitting element to the mounting surface.The bonding member covers at least a portion of the first metal patternand at least a portion of the second metal pattern.

According to another embodiment, a method of manufacturing a lightemitting device includes providing a support member having a mountingsurface. The support member includes an insulating member having topsurface and a plurality of side surfaces, a first metal pattern disposedon the top surface of the insulating member, and a second metal patterndisposed on the side surface of the insulating member such that a sidesurface of the second metal pattern is continuous with a top surface ofthe first metal pattern. The method further includes providing a lightemitting element, depositing a bonding member onto one or more of: (i)the mounting surface and (ii) the light emitting element, and mountingthe light emitting to the support substrate at a location of the firstmetal pattern such that the bonding member bonds the light emittingelement to the mounting surface and the bonding member covers at least aportion of the first metal pattern and at least a portion of the secondmetal pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view depicting a supporting member according to anembodiment of the present invention.

FIG. 2A is a front view depicting the supporting member of FIG. 1 and alight emitting element to be mounted on the supporting member.

FIG. 2B is a top view depicting the supporting member and light emittingelement of FIG. 2A with the light emitting element mounted on thesupporting member.

FIG. 3 is a front cross-sectional view depicting the supporting memberand light emitting element of FIG. 2A along the cross-section A-A, asindicated in FIG. 1.

FIG. 4 is a top view depicting a supporting member according to anotherembodiment of the present invention.

FIG. 5 is a front view depicting the supporting member of FIG. 4 and alight emitting element to be mounted on the supporting member.

FIG. 6 is a front cross-sectional view depicting the supporting memberand light emitting element of FIG. 5 along the cross-section B-B, asindicated in FIG. 4.

FIG. 7A is a top view depicting a light emitting device according to anembodiment of the present invention.

FIG. 7B is a front cross-sectional view depicting the light emittingdevice of FIG. 7A along the cross-section C-C, as indicated in FIG. 7A.

FIG. 8A is a top view depicting a light emitting device according toanother embodiment of the present invention.

FIG. 8B is a front cross-sectional view depicting the light emittingdevice of FIG. 8A along the cross-section D-D, as indicated in FIG. 8A.

FIG. 9A is a top view depicting a light emitting device according toanother embodiment of the present invention.

FIG. 9B is a front cross-sectional view depicting the light emittingdevice of FIG. 9A along the cross-section E-E, as indicated in FIG. 9A.

FIG. 10A is a top view depicting a light emitting device according toanother embodiment of the present invention.

FIG. 10B is a front cross-sectional view depicting the light emittingdevice of FIG. 10A along the cross-section F-F, as indicated in FIG.10A.

DETAILED DESCRIPTION

The supporting members and light emitting devices according toembodiments of the present invention are explained below with referenceto the accompanying drawings, in which the sizes of or positionalrelationships between some parts of the semiconductor light emittingelements may be exaggerated for clarification. In addition, in thefollowing explanations, identical or equivalent elements or constituentsmay be indicated by the same denotations or similar reference numbersthrough the embodiments, and descriptions of the identical or equivalentelements or constituents are not repeated through the explanations ofthe embodiments unless necessary.

First Embodiment

A supporting member 100 according to a first embodiment is shown in FIG.1 to FIG. 3. FIG. 1 is a top view depicting a supporting member 100according to the first embodiment of the present invention. Thesupporting member 100 is a member on which a light emitting element maybe mounted. FIG. 1 depicts a supporting member 100 before a lightemitting element has been mounted. The supporting member 100 includes aninsulating member 101 having a top surface and side surfaces. A firstmetal pattern 106 is disposed on the planar top surface of theinsulating member 101.

FIG. 2A is a front view of the supporting member 100 of FIG. 1,illustrating the light emitting element 102 being mounted on thesupporting member 100.

FIG. 2B is a top view depicting the light emitting element 102 mountedon the supporting member 100. The supporting member 100 is shown throughthe light emitting element 102. The light emitting element 102 includeselectrodes 103. A first electrode 103 a may, for example, be a positiveelectrode, while a second electrode 103 b may, for example, be anegative electrode. The contour of the light emitting element 102 andthe pattern of the electrodes 103 are shown in dotted lines in FIG. 2B.The portions shown in light shading are the contact portions between thefirst metal pattern 106 (106 a and 106 b) of the supporting member 100and the electrodes 103 of the light emitting element 102.

FIG. 3 is a front cross-sectional view depicting the supporting member100 and light emitting element 102 of FIG. 2A along the cross-sectionA-A, as indicated in FIG. 1. The arrows in FIG. 3 indicate light emitteddownward from the light emitting element.

In the embodiment shown in FIGS. 1-3, the supporting member 100 may havean approximately cuboid shape (though sides of the insulating member 101may have concave cut-out sections, as discussed below). The mountingsurface for the light emitting element 102 may have an approximatelysquare shape.

The planar shape of the light emitting element 102 may approximatelycorrespond to the shape of the mounting surface of the supporting member100.

The mounting surface of the supporting member 100 may include the firstmetal pattern 106 for connecting the light emitting element 102 with therespective electrodes 103.

The center portion of each side of the insulating member 101 may have aconcave cut-out section 104. The cut-out section 104 may be formed as ahalf ovular through-hole that extends from the upper surface to thelower surface of the insulating member 101. Thus, each cut-out section104 may have a flat center portion and curved side portions, as depictedin FIG. 1.

The first metal pattern 106 includes one or more first terminals 106 aand second terminals 106 b. In FIG. 1, for example, the first metalpattern includes one first terminal 106 a and two second terminals 106b. The first terminal 106 a may, for example, be a positive terminal,while the second terminal 106 b may, for example, be a negativeterminal. The first terminal 106 a may be formed in approximately thecenter of the mounting surface of the supporting member 100. The firstterminal 106 a may have a protrusion at each of a pair of opposite sidesof the first terminal 106 a (depicted at the top and bottom of the firstterminal 106 a in FIG. 1). The protrusion may be in contact with and/orintegral with a second metal pattern 108 disposed on a cut-out section104 of each of a pair of corresponding opposing side surfaces of theinsulating member 101, as shown, for example, in FIG. 2A. Thus, the sidesurface of the second metal pattern 108 may be continuous with the topsurface of the first terminal 106 a of the first metal pattern 106.

The first terminal may one or more concave portions. The concaveportions may be on opposing sides of the first terminal. The secondterminal 106 b may be disposed on the mounting surface such that aportion of the second terminals 106 b interposes a concave portion ofthe first terminal 106 a. The second terminals 106 b may have asemicircular shape.

As shown in FIG. 2B, the first terminal 106 a may have a portion that issmaller in width than the corresponding portion of the first electrode103 a. The width of the first terminal 106 a between the concaveportions may be larger than the width of the corresponding portion ofthe first electrode 103 a. The second terminal 106 b may have across-sectional area that is larger than the corresponding secondelectrode 103 b. The shapes of the first and second terminals 106 a and106 b may be adopted according to the shapes of the electrodes 103 ofthe light emitting elements 102 at the positions at which the electrodes103 are connected.

The second metal pattern 108 may be disposed on each of a pair of sidesurfaces of the insulating member 101. The second metal pattern 108 maybe disposed on each side surface of the insulating member 101. Thesecond metal pattern 108 may be formed such that side surfaces of thesecond metal pattern 108 are continuous with top surfaces of the firstterminals 106 a and/or the second terminals 106 b. The second metalpattern 108 may be disposed from the upper surface of the insulatingmember 101 to the lower surface of the insulating member 101, such thatthe second metal pattern covers part of the flat center portion of thecut-out section 104.

The light emitting element 102 is bonded to the first metal pattern 106through a bonding member 110, as shown in FIG. 3. The bonding member 110is applied such that it covers at least a part of the second metalpattern 108. That is, because the first metal pattern 106 and the secondmetal pattern 108 are continuous with each other, when the bondingmember material squeezed out from between the first metal pattern 106and the electrodes 103 during bonding, an excess amount of the materialwill spread to the second metal pattern 108. The configuration of themetal patterns 106 and 108 allows the excess bonding member material tobe directed to a surface other than the light emitting element mountingsurface. It is thereby possible to avoid light emitted from the lightemitting element 102 from being absorbed by bonding member material thatis squeezed out onto the mounting surface. Unabsorbed light emitteddownwardly may be extracted from the upper surface by being reflected bya light-reflecting member provided on a member for mounting thesupporting member 100, or may be extracted directly from the lowersurface.

The metal patterns 106 and 108 have a higher wettability than theinsulating member 101. Therefore, due to the configuration of the metalpatterns 106 and 108, the bonding member may spread to the surfaces ofthe metal patterns 106 and 108 rather than the surface of the insulatingmember 101. When the metal patterns 106 and 108 are not formed to extendout from directly under the light emitting element 102, there is no wayto direct the direct the excess material from the bonding member. Thus,unevenness in the amount of applied bonding member material may affectthe thickness of the bonding member, cause a tilt in the mounted lightemitting element 102, and cause a positional deviation in the mountingposition. For at least these reasons, it is desirable to provide themetal patterns 106 and 108, by which the bonding member material canspread outward from directly under the light emitting element.

Furthermore, when the light emitting element 102 and the supportingmember 100 are bonded only at the portion directly under the lightemitting element 102, the condition of the bonding member 110 cannot beobserved from the outside. When the bonding member material is squeezedoutward from beneath the light emitting element using the metal patterns106 and 108, the condition of the bonding member can be easilydetermined by viewing the amount of bonding member material that hasbeen squeezed onto the metal patterns 106 and 108. The ability of thebonding member material to spread outward from beneath the lightemitting element 102 via the metal patterns 106 and 108 is valuable interms of ease of manufacturing.

The configuration of the metal patterns 106 and 108, having a higherwettability than the insulating member 101, prevents the bonding membermaterial from spreading to locations on which the light emitted from thelight emitting element 102 is directly incident. Thus, light emittingdevices that include the supporting member 100 have highly efficientlight extraction properties, and have fewer problems related to thetilting and positional deviation of the light emitting element 102.

Supporting Member

The supporting member 100 is a member for mounting the light emittingelement 102. The supporting member is sometimes called a “packagesubstrate” or “submount.” The supporting member may have various shapes,such as a cuboid, a cube, a column, or a prism. As explained above, thefirst metal pattern 106 is disposed on the upper surface of theinsulating member 101 such that it is a part of the upper surface of thesupporting member 101, and the second metal pattern 108 is disposed onthe side surfaces of the insulating member 101 such that it is a part ofthe side surfaces of the supporting member 100.

Examples of materials that can be used for the insulating member 101 ofthe supporting member 100 include a glass epoxy, a resin, and ceramics.It is preferable that the insulating member 101 be made from ceramicmaterials such as alumina, aluminum nitride, and mullite, which alloweasy formation of the metal patterns 106 and 108 on its surface whilehaving good heat resistance and weather resistance properties. Aninsulating member 101 made of ceramics may be provided with aninsulating layer made of insulating materials other than ceramics.Examples of such insulating material include a BT resin, a glass epoxy,and an epoxy-based resin. In order to suitably dissipate heat generatedfrom the light emitting elements 102, the materials of the insulatingmember 101 preferably have a thermal conductivity of 150 W/m·K orhigher. The insulating member 101 may alternatively be made of a metalmember having insulating portions.

It is preferable that either the side surface on which the second metalpattern 108 is disposed is substantially coplanar with a correspondingside surface of the light emitting element 102, or that the side surfaceof the light emitting element 102 extends beyond the side surface onwhich the second metal pattern 108 is disposed. In this way, the portionof the bonding member 110 that is squeezed from between the first metalpattern 106 and the electrodes 103 is not located in areas where lightfrom the light emitting element 101 tends to be absorbed. In thisspecification, the term “substantially coplanar” means within 500 μm ofplanar. When discussing planarity for embodiments in which thesupporting member 100 comprises a cut-out section 104 in the sidesurface of the insulating member 101, the term “side surface” refers tothe section of the side surface without the cut-out section 104.

It is preferable that that a cut-out section 104 is located in a sidesurface of the insulating member 101 and that the second metal pattern108 is disposed in the cut-out section 104. In the embodiment shown inFIG. 3, for example, the side surface of the light emitting element 102extends beyond the side surface of the second metal pattern 108. Thesecond metal pattern does not necessarily cover the entire cut-outsection 104.

Cut-Out Section

The cut-out section 104 in a side surface of the supporting member 100is formed by cutting out a portion of the a side surface of theinsulating member 101. Disposing the second metal pattern 108 on aportion of the cut-out section 104 allows the bonding member 110 to bearranged within the cut-out section 104. As shown in FIG. 2A, thecut-out section 104 may extend from the upper surface to the lowersurface of the insulating member 101. The second metal pattern 108 canbe disposed such that it extends to the lower surface of the insulatingmember 101, such that electric contact can easily be established fromthe lower surface of the supporting member 100. The cut-out section 104may have any shape and need not extend from the upper surface of theinsulating member 101 to the lower surface of the insulating member 101,as long as the first and second metal patterns 106 and 108 can bedisposed such that the excess bonding member material can be directedoutward toward the side surface of the supporting member 100.

As shown in FIG. 1, it is preferable that at least two opposing sides ofthe insulating member 101 (and more preferably, all the side surfaces ofthe insulating member 101) have a cut-out section 104. This is becausethe use of cut-out sections reduces the amount bonding member materialthat is located near the light emitting element 102.

Light Emitting Element

The light emitting element 102 to be mounted on the supporting member100 is not specifically limited and any known light emitting elementscan be used, but a light emitting diode is preferably used as the lightemitting element 102. A light emitting element of any appropriatewavelength can be employed. For example, for a light emitting elementcapable of emitting blue or green light, a light emitting element usingZnSe, a nitride-based semiconductor (In_(x)Al_(y)Ga_(1-x-y)N, 0≦X, 0≦Y,X+Y≦1), or GaP may be employed. For a light emitting element capable ofemitting red light, GaAlAs, AlInGaP, or the like may be employed. Asemiconductor light emitting element made of a material other than theabove may also be employed. The composition, color of emitted light,size, and number of the light emitting elements to be employed can beselected appropriately according to their purpose. If a light emittingdevice having a fluorescent material is used, it is suitable to employ anitride semiconductor (In_(x)Al_(y)Ga_(1-x-y)N, 0≦X, 0≦Y, X+Y≦1) capableof emitting light of a short wavelength that can efficiently excite thefluorescent material. The emission wavelength can be varied by thematerials and the content ratio of the mixed crystal of thesemiconductor layer. The positive and negative electrodes may bedisposed on the same surface or the positive and negative electrodes maybe disposed on different surfaces.

The light emitting element 102 of the present embodiment has a pair ofpositive and negative electrodes on the same surface. The pair ofelectrodes are mounted in flip-chip manner (such that the electrodesface the upper surface of the supporting member 100) on the respectivemetal patterns 106 of the supporting member 100 through the conductivemember 110, and the surface opposite from the surface where theelectrodes are mounted is arranged as the light extracting surface. Thelight emitting element 102 may be formed by stacking layers of nitridesemiconductors on a light transmissive sapphire growth substrate, inwhich the sapphire substrate is arranged at the upper surface side ofthe light emitting element 102 so as to be the light extracting surface.The sapphire substrate may have unevenness in the bonding surface withthe nitride semiconductor layer, and accordingly, the critical angle ofthe light emitted from the nitride semiconductor layer incident on thesapphire substrate can be altered intentionally, which facilitatesextraction of light out of the sapphire substrate. The growth substratemay be removed, by using, for example, LLO (Laser Lift Off) or the like.Such growth substrate is not limited to a sapphire substrate and can beappropriately changed.

In the present embodiment, as shown in FIG. 2B and the schematiccross-sectional view in FIG. 3, a pair of negative electrodes 103 b maybe formed interposing the positive electrode 103 a, and each of theelectrodes may be connected to the first metal patterns 106 a, 106 bthrough the bonding member 110. Each of the first terminals 106 a towhich the positive electrode 103 a of the light emitting element 102 isconnected and the second terminals 106 b to which the negative electrode103 b of the light emitting element 102 is connected may be providedwith a second metal pattern 108 which is disposed on a side surface ofthe insulating member 101. The second metal pattern 108 may be formedsuch that side surfaces of the second metal pattern 108 are continuouswith top surfaces of the first terminals 106 a and/or the secondterminals 106 b, such that the bonding member 110 may be wet spread onthe second metal patter 108. In the present embodiment, each of theelectrodes of the light emitting element 102 is directly bonded by usingthe conductive bonding member 110, so that the first metal pattern 106and the second metal pattern 108 also serve as the conductive wiring forsupplying electric current to the light emitting element 102.

First Metal Pattern and Second Metal Pattern

The first metal pattern 106 may disposed on the upper surface of theinsulating member 101. The first metal pattern 106 may be disposed atportions adjacent to respective side surfaces so as to connect to thesecond metal pattern 108 disposed on the side surfaces of the insulatingmember 101. The shape of the first metal pattern 106 can beappropriately changed according to the shape of the electrodes 103 ofthe light emitting element 102 to be mounted.

The materials of the first metal pattern 106 and the second metalpattern 108 can be appropriately selected depending on the material ofthe insulating member 101 and the method of manufacturing. For example,when a ceramic is used as the material of the insulating member 101, thematerials of the first metal pattern 106 and the second metal pattern108 preferably have a high melting point so as to be able to endure thefiring temperature of the ceramic sheet. A metal having a high meltingpoint such as tungsten and molybdenum is preferable. A different metalmaterial may be applied to coat the upper surface of the first metalpattern 106 and second metal pattern 108 by way of plating or the like.

When a glass epoxy resin or the like is used for the material of theinsulating member 101, the first metal pattern 106 and the second metalpattern 108 are preferably made of a material that is easy to process.When an injection-molded epoxy resin is used as the material of theinsulating member 101, the first metal pattern 106 and the second metalpattern 108 are preferably made of a material that has a relatively highmechanical strength and is easy to process by way of punching, etching,bending, or the like. Examples of such materials include a metal such ascopper, aluminum, gold, silver, tungsten, iron, and nickel oriron-nickel alloy, phosphor bronze, copper-iron alloy and molybdenum.

The surface of the metal patterns may further be covered with a metalmaterial, which is not specifically limited. Examples of such metalmaterials include silver, or an alloy of silver and a metal having highreflectance such as copper, gold, aluminum, or rhodium, or a multilayerfilm using silver and such alloys. The metal material may be disposed byway of plating or other techniques such as sputtering or vapordeposition.

Bonding Member

The bonding member 110 is a member for bonding the electrodes 103 of thelight emitting element 102 and respective first metal patterns 106.Examples of appropriate bonding member materials include an Au alloy, anAg alloy, a Pd alloy, an In alloy, a Pb—Pd alloy, an Au—Ga alloy, anAu—Sn alloy, a Sn alloy, an Au—Ge alloy, an Au—Si alloy, an Al alloy,and/or a Cu—In alloy. The bonding member material may be a mixture of ametal and a flux. For some embodiments, the bonding member need not beconductive. Rather, an insulating resin (resin composition) such as anepoxy resin or a silicone resin can be used.

When the light emitting element 102 is mounted in flip-chip manner, aconductive member may be used for the bonding member 110 to electricallyconnect the electrodes 103 of the light emitting element 102 and therespective first metal pattern 106. When electric connection is notneeded, for example, when bonding the insulating substrate side of thelight emitting element, an insulating resin or the like may be used. Thebonding member 110 described above may be disposed as a single member oras a combination of several different members. When a light transmissivebonding member is used, a fluorescent member capable of absorbing thelight from the semiconductor light emitting element and emitting lightof different wavelength can be contained in the bonding member.

Bonding of the Light Emitting Element

An example of a method of bonding the light emitting element 102 and thefirst metal pattern 106 will be illustrated below.

In one embodiment, shown in FIG. 2A, the electrodes of the lightemitting element 102 are placed opposite the first metal pattern 106 andbonded through a bonding member 110 (not shown in FIG. 2A). The amountof bonding member material is such that the bonding member material issqueezed out from the bottom surface of the light emitting element 102and extends to the second metal pattern 108.

For example, when a Au—Sn paste is used as the bonding member, thebonding member made of the Au—Sn paste may be applied on the first metalpattern 106 of the supporting member 100 and the light emitting element102 may disposed on the Au—Sn paste. Alternatively, a metal bondingmember material may be applied beforehand on the electrodes 103 of thelight emitting element 102 and then the light emitting element 102 maybe disposed on the first metal pattern 106. Thereafter, heat may beapplied to melt the metal bonding member. When there is a difference inwettability in the insulating member 101 and the first metal pattern106, such as when the insulating material is a ceramic, the metalbonding member material is repelled at the ceramic portion and wetspreads along the first metal pattern 106. Even when bonding membermaterial is covers portions of both the first metal pattern 106 and theinsulating member 101, the hot-melted bonding member tends to spreadalong the first metal patter 106 due to the difference in wettability.Furthermore, due to the configuration of the first metal pattern 106 andsecond metal pattern 108, the melted bonding member material wet spreadsto the second metal pattern 108 disposed continuous to the respectivefirst metal patterns 106.

Covering the first metal pattern 106 and the second metal pattern 108 asdescribed above enables improvement in the bonding strength of the lightemitting element 102 and the supporting member 100, and reducesunevenness in the thickness of the bonding member 110. Also, directingthe squeezed-out portion of the bonding member to the second metalpatterns 108 located on the respective side surfaces of the insulatingmember 101 as described above allows a configuration where the lightfrom the light emitting element is not incident on the squeezed-outportion of the bonding member 110, and thus reduces absorption of lightincident on the squeezed-out portion of the bonding member 110.

The bonding member 110 may cover only a part of the second metal patter108, and need not cover the entire second metal pattern 108.

Third Metal Pattern

Further, the supporting member 100 according to the present embodimentmay include a third metal pattern 114 on the lower surface of theinsulating member 101, as shown in FIG. 3. The bottom surface of thethird metal pattern 114 may be continuous with the side surface of thesecond metal pattern. Disposing a third metal pattern 114 on the lowersurface of the insulating member 101 allows further mounting of thesupporting member 100 on another substrate or the like with easyestablishment of electrical connection.

Second Embodiment

A supporting member 200 according to a second embodiment is shown inFIG. 4 to FIG. 6. FIG. 4 is a top view depicting a supporting member 200according to the second embodiment of the present invention.

FIG. 5 is a front view of the supporting member 200 of FIG. 4,illustrating the light emitting element 102 being mounted on thesupporting member 200.

FIG. 6 is a front cross-sectional view depicting the supporting member200 and light emitting element 102 of FIG. 4 along the cross-sectionB-B.

In the present embodiment, the center portion of each side of theinsulating member 101 may have one or more concave cut-out sections 204.Each cut-out section 204 may have a semicircular column shapepenetrating from the upper surface to the bottom surface of theinsulating member 101. A metal member 115 may be embedded in each of thecut-out sections 204. The side surface of the metal member may becoplanar with the side surface of the insulating member 101 such thatside surfaces of the supporting member 200 are flat.

In FIG. 4, first conductive patterns 206 are shown in light shading. Theportions at which the metal member 115 are embedded in the insulatingmember 101 are shown in cross-hatching. Each metal member 115 may bedisposed such that its outer surface is approximately in the same planewith the light emitting element mounting surface and the correspondingside surface of the supporting member 100. In the second embodiment, thepart of the metal member 115 that is exposed on the light emittingelement mounting surface serves as a part of the first metal pattern 206and the part of the metal member 115 that is exposed on the sidesurfaces of the supporting member 200 serves as a part of the secondmetal pattern 208. Filling the cut-out portions 204 with the metalmember allows increased thickness of the metal patterns, so that theelectrical resistance of the supporting member 200 can be reduced.

The present embodiment may utilize the same configuration as in thefirst embodiment except as described below.

First Metal Pattern and Second Metal Pattern

In the present embodiment, the same materials used for the metalpatterns of the first embodiment can be used as the material of themetal member 115 to be embedded in the cut-out portions 204.

The cut-off portions 204 and the metal members 115 can be formed bydefining through and/or non-through holes in a substrate to be formedinto a plurality of supporting members connected in rows and columns. Ametal member may be filled in the holes, and the individual supportingmembers may be separated by dividing the substrate along the metalmembers. In this way, each of the side surfaces of the insulating member101 and the corresponding side surfaces of the metal members 115 can beapproximately on the same plane. This allows manufacture of thesupporting member 200 in which the first metal members 206 are exposedat the light emitting element mounting surface of the supporting member200 and the first and the second metal patterns are formed continuously.That is, the cut surfaces of the metal member 115 form the second metalpatterns 208. A different metal material may be applied on the exposedmetal member. The shape of the metal member 115 is not limited to asemi-circular column and may be a rectangular column, a triangularprism, or any other appropriate shape. That is, the cross sectionalshape defining the corresponding cut-out portions is not limited to asemi-circular shape and a V-shape or other recess shape may be employed.

The respective electrodes 103 of the light emitting element 102 may bebonded to the first metal pattern 206 of the supporting member 200through the bonding member 110, as shown in FIG. 5 and FIG. 6. Thesupporting member 200 of the present embodiment may have a metal memberapplied thereto, so that the electrical resistance can be reduced andheat dissipating property can be improved.

Also, in the same manner as in the first embodiment, absorption of lightby the bonding member 110 can be reduced and the light extractionefficiency can be improved. Thus the same effects as in the firstembodiment can be obtained.

Third Embodiment

As the third embodiment, a light emitting device 300 using a supportingmember 100 is shown in FIGS. 7A and 7B.

FIG. 7A is a top view depicting a light emitting device according to anembodiment of the present invention.

FIG. 7B is a front cross-sectional view depicting the light emittingdevice of FIG. 7A along the cross-section C-C, as indicated in 7A.

The supporting member 100 having a light emitting element 102 mountedthereon as described in the first embodiment is mounted on the basemember 112, and the covering member 120 is disposed to cover thesupporting member 100 and the light emitting element 102.

Base Member

Any material capable of mounting the supporting member 100 andestablishing electric connection with it can be used for the base member112.

The same materials used in forming the insulating member 101 of thesupporting member 100 can be employed in the base member 112. Examplesinclude an insulating member such as a glass epoxy, a resin, andceramics. A metal material having an insulating member disposed thereonmay also be used. A base member 112 made of the same material as theinsulating member 101 is preferable, because this will allow both thebase member 112 and insulating member 101 to have the same heatdissipating coefficient, suppressing the occurrence of cracks and thelike. Also, by using the same material as that in the supporting member,the base member 112 and the insulating member 101 may be formedintegrally so that the insulating member 101 is included as a part ofthe base member 112.

The base member 112 may have a plate shape or may have a cavity. In theembodiment shown in FIGS. 7A and 7B, the base member 112 has anapproximately square external shape which is approximately the same inshape (though different in size) as the light emitting element 102, andhas a circular cavity. The supporting member 100 may be mounted in thecavity such that the top surface of the supporting member 100 protrudeshigher than the top surface of the base member.

The third metal pattern 114 may be disposed on the lower surface of theinsulating member 101 and bonded to the electrically conductive pattern117 disposed in the cavity of the base member 112. Further, theelectrically conductive pattern 117 is electrically connected to theexternal electrodes 118 a, 118 b on the bottom surface of the basemember 112 through the use of vias 119.

In the embodiment shown in FIG. 7B, both of the metal patterns disposedon the bottom of the supporting member 100 may be negative terminals andelectrically connected to the negative external electrodes 118 b. Thepositive electrode of the light emitting element is connected to theexternal electrode 118 a (not shown) through the patterns disposed onthe surface of the supporting member and the surface of the basematerial.

A light-reflecting member 116 may be arranged to cover the conductivepattern 117 at the surface in the cavity. Thus, covering the secondmetal pattern 108 with the bonding member 110 allows the reflection oflight propagating toward the bottom surface in the cavity without beingabsorbed by the bonding member, and thus improves the extraction oflight.

Light Reflective Material

The light-reflecting member 116 is a member capable of efficientlyreflecting light emitted from the light emitting element 102 andpreferably made of an insulating material that absorbs little light andhas high resistance against light and heat. Examples of suitablematerials include a silicone resin, an epoxy resin, and a urea resin. Inaddition to these materials, a coloring agent, a light diffusing agent,a light reflecting material, various fillers, a wavelength convertingmaterial (a fluorescent material) or the like may also be included asrequired. When a resin material is employed, the light-reflecting member116 can be easily formed by filling the cavity with the resin materialto cover the electrically conductive pattern 117. Disposing the resinmaterial to cover the electrically conductive pattern 117 and otherssuch as second metal pattern 108 and the bonding member 110 enablesfurther improvement in the light extracting efficiency. Thelight-reflecting member 116 may be made of an inorganic material. Theelectrically conductive pattern 117, the second metal pattern 108, thebonding member 110, and the like may be covered by applying a lightreflective filler by way of electrodeposition coating.

According to the light emitting device of the present embodiment,practically no light from the light emitting element 102 mounted on thesupporting member 100 is absorbed by the bonding member 110. Mounting onthe base material 112 and covering the surface in the cavity with thelight-reflecting member 116 makes it possible to obtain a light emittingdevice having further improved light extraction efficiency.

Appropriately adjusting the shape of the covering member 120 to be in,for example, a semicircular lens shape as shown in FIGS. 7A and 7B,makes it possible to obtain a desired distribution of light. Thecovering member 120 is not specifically limited provided that it allowsextraction of light emitted from the light emitting element to theoutside. A light transmissive sealing member for sealing the cavity, ahollow lens or cover, or the like can be used as the covering member120. The kind of the lens can be appropriately selected according to thedesired distribution of light.

Fourth Embodiment

As the fourth embodiment, a light emitting device 400 using a supportingmember 100 is shown in FIGS. 8A and 8B.

FIG. 8A is a top view depicting a light emitting device according toanother embodiment of the present invention.

FIG. 8B is a front cross-sectional view depicting the light emittingdevice of FIG. 8A along the cross-section D-D, as indicated in FIG. 8A.

The light emitting device 400 may have the same structure as that of thethird embodiment except that the light emitting element 102 has a pairof electrodes arranged at the upper and lower sides thereof. Theelectrode disposed on the top surface and the electrically conductivepattern 117 are connected by the conductive wire 122. In the embodimentshown in FIGS. 8A and 8B, the light-reflecting member is not disposed inthe cavity, but the surface of the electrically conductive pattern 117is covered with a material having high light reflectance (such assilver, gold, rhodium, or the like), and capable of exhibiting the sameeffects as the configuration described in the third embodiment.

Fifth Embodiment

As the fifth embodiment, FIGS. 9A and 9B show a light emitting device500 using a supporting member 100.

FIG. 9A is a top view depicting a light emitting device according toanother embodiment of the present invention.

FIG. 9B is a front cross-sectional view depicting the light emittingdevice of FIG. 9A along the cross-section E-E, as indicated in FIG. 9A.

The light emitting device 500 has substantially the same structure asthat is the third embodiment except that the light emitting element 102has a pair of electrodes at the same surface side (the top side in FIGS.9A and 9B) and is mounted on the first metal pattern of the supportingmember using the insulating substrate as the mounting surface. Theelectrodes at the top surface of the light emitting element 102 and theelectrically conductive patterns 117 of the base material are connectedby the electrically conductive wires 122. The first metal pattern isformed such that it doesn't have a positive nor a negative electricpotential. The light emitting device 500 of the present embodiment isalso capable of exhibiting the same effects as in the third embodiment.

Sixth Embodiment

As the sixth embodiment, FIGS. 10A and 10B show a light emitting device600 using a support member 100.

FIG. 10A is a top view depicting a light emitting device according toanother embodiment of the present invention.

FIG. 10B is a front cross-sectional view depicting the light emittingdevice of FIG. 10A along the cross-section F-F, as indicated in FIG.10A.

In this embodiment, the electrically conductive pattern 117, the secondmetal pattern 108, and the bonding member 110 are covered with thelight-reflecting member 116. A resin material may be used for thelight-reflecting member 116. Further, as shown in FIG. 10B, thelight-reflecting member 116 may be disposed such that the bottom surfaceof the light emitting element 102 is covered with the light-reflectingmaterial 116. Thus, the first metal pattern 106 and the electrodesrespectively bonded to the corresponding portion of the first metalpattern 106 can be covered by the light-reflecting member 116. When thelight emitting element 102 is mounted on a flat surface, for example asshown in FIG. 9B, it can be difficult to dispose the light-reflectingmember such that the top of the light-reflecting member terminates atthe bottom surface of the light emitting element. However, providing thesupporting body 100 in the cavity defined in the base member 112, asshown in FIG. 9B, makes it easier to cover all of the first metalpattern 106, second metal pattern 108 and bonding member 110 disposed onthese metal patterns with the light-reflecting member 116. Thus, thelight extraction efficiency can be further improved.

The light-reflecting member 116 can also serve as an under-fill whichenables suppression of separation of light emitting element 102 due toexpansion stress exerted on the covering member 120 caused by thermalshock. Further, occurrence of voids in the covering member 120originating from beneath the light emitting element 102 can beprevented. The portions other than the portions where thelight-reflecting member 116 is disposed are substantially the same asthat in the third embodiment and the same effects can be obtained.

INDUSTRIAL APPLICABILITY

The supporting member according to the present invention and the lightemitting device using the supporting member are capable of suppressingabsorption of light by the bonding member and have excellent lightextraction efficiency. The supporting members according to the presentinvention and the light emitting devices using the supporting devicescan be utilized in applications such as various indicators, lightingapparatus, displays, backlight light sources for liquid crystaldisplays, and further, facsimiles, copiers, image reading systems inscanners or the like, and projector devices.

While the preferred embodiments of the devices and methods have beendescribed in reference to the environment in which they were developed,they are merely illustrative of the principles of the inventions.Modification or combinations of the above-described assemblies, otherembodiments, configurations, and methods for carrying out the invention,and variations of aspects of the invention that are obvious to those ofskill in the art are intended to be within the scope of the claims.

What is claimed is:
 1. A method of manufacturing a light emitting device, the method comprising: providing a structure comprising: an insulating substrate to be divided into a plurality of light emitting devices, the substrate having a plurality of holes, including a hole on at least one side of each area corresponding to each respective light emitting device, a plurality of metal members disposed on the substrate, each metal member having a first portion disposed on a planar top surface of the substrate, and at least one second portion disposed in at least one of the holes in the substrate, and a plurality of light emitting elements, each light emitting element being mounted on a respective one of the metal members; dividing the substrate through the holes to form a plurality of light emitting devices, such that each light emitting device includes: an insulating member having a top surface and a plurality of lateral surfaces, a first metal pattern disposed on a top surface of the insulating member, a second metal pattern disposed on at least one of the lateral surfaces of the insulating member, a cut-out section in at least one of the lateral surfaces of the insulating member, and a light emitting element disposed on the first metal pattern, wherein at least a portion of the second metal pattern is disposed in the cut-out section.
 2. The method of claim 1, wherein a lateral surface of the second metal pattern is continuous with a top surface of the first metal pattern.
 3. The method of claim 1, wherein the plurality of holes in the insulating substrate includes a hole on each side of each area corresponding to each respective light emitting device such that, when the substrate is divided, a cut-out section is formed in each of the side surfaces of the insulating members, at least a portion of the second metal pattern is disposed in each cut-out section.
 4. The method of claim 2, wherein the plurality of holes in the insulating substrate includes a hole on each side of each area corresponding to each respective light emitting device such that, when the substrate is divided, a cut-out section is formed in each of the side surfaces of the insulating members, at least a portion of the second metal pattern is disposed in each cut-out section
 5. The method of claim 1, wherein, the second portion of each metal member fills a respective one of the holes, such that, when the substrate is divided, each second metal pattern is embedded in a cut-out section, and a side surface of the second metal pattern is substantially coplanar with a corresponding side surface of the insulating member.
 6. The method of claim 3, wherein, the second portion of each metal member fills a respective one of the holes, such that, when the substrate is divided, each second metal pattern is embedded in a cut-out section, and a side surface of the second metal pattern is substantially coplanar with a corresponding side surface of the insulating member.
 7. The method of claim 1, wherein the metal members are disposed on the substrate such that, when the substrate is divided, the first metal pattern of each light emitting device includes one first terminal located in a center of a top surface of the light emitting device, and two second terminals located laterally of first terminal.
 8. The method of claim 3, wherein the metal members are disposed on the substrate such that, when the substrate is divided, the first metal pattern of each light emitting device includes one first terminal located in a center of a top surface of the light emitting device, and two second terminals located laterally of first terminal.
 9. The method of claim 6, wherein the metal members are disposed on the substrate such that, when the substrate is divided, the first metal pattern of each light emitting device includes one first terminal located in a center of a top surface of the light emitting device, and two second terminals located laterally of first terminal.
 10. The method of claim 5, wherein the metal members are disposed on the substrate such that, when the substrate is divided, the first terminal includes protrusions extending from two opposing sides of the first terminal.
 11. The method of claim 10, wherein the metal members are disposed on the substrate such that, when the substrate is divided, the first terminal includes concave portions on two other opposing sides of the first terminal.
 12. The method of claim 11, wherein the metal members are disposed on the substrate such that, when the substrate is divided, each second terminal interposes one of the concave portions of the first terminal.
 13. The method of claim 1, wherein the insulating substrate is made of a glass epoxy, a resin, or a ceramic.
 14. The method of claim 1, wherein the insulating substrate is made of alumina, aluminum nitride, or mullite.
 15. The method of claim 1, wherein the metal members are made of at least one material selected from the group consisting of copper, aluminum, gold, silver, tungsten, iron, nickel alloy, iron-nickel alloy, phosphor bronze, copper-iron alloy, and molybdenum.
 16. The method of claim 1, further comprising applying a coating material to an upper surface of the metal members, wherein the coating material is different than a material of the metal members.
 17. The method of claim 1, wherein the holes are shaped such that, when the substrate is divided, the second metal pattern has a shape of a semi-circular column, a rectangular column, or a triangular prism.
 18. The method of claim 1, wherein the holes in the substrate are through-holes.
 19. The method of claim 1, wherein the step of providing said structure comprises forming said metal members on the substrate.
 20. The method of claim 1, wherein the step of providing said structure comprises mounting the light emitting elements on the respective metal members. 